Such a device is disclosed in GB 1 506 074. In this publication a rotary holder part is described, the rotation of which is achieved with a motor, which is not shown and which is connected via a V-belt to a pulley located beneath the bottom part. The rotation shaft is of hollow construction and a shaft can move up and down inside it under the influence of a magnet fitted outside it in order to be able to open the holder part to remove or supply coffee.
This is a complex construction that takes up a great deal of space and moreover is not easy to clean. As a result of the use of a magnet the problem arises that either there is insufficient force for opening the holder or opening takes place with an appreciable jolt.
In the British patent specification, after the water has been propelled through the rotating filter with the powder layer thereon it is fed into a coffee collection chamber and from there directly to a discharge, from which a cup of coffee can be drawn off. The collection chamber downstream of the filter is many times larger than the volume of a single cup of coffee.